In quantum information theory, entanglement is a vital resource for
some practical applications such as quantum cryptography, quantum
teleportation and quantum computation [1]}, [2]}. During
the last decade, this inspired a great deal of effort for detecting
and quantifying the entanglement
[3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}. On
the other hand, the creation and distribution of entanglement is
also of central interest in quantum information processing. More
specially the distribution of bipartite entanglement is a key
ingredient for performing certain quantum-information processing
tasks such as teleportation.
